Airplane travel. By itself does not cause hemorrhoids. But air travel can cause severe dehydration, leading to constipation at conclusion of flight and thus straining and a flare of hemorrhoids. You lose 20 ounces of fluids per hour of air travel just sleeping on the plane. I recommend drinkingat least 20 ounces every hour of air travel and must be caffeine free/alcohol free fluids, to avoid constipation.